I dont think it is because they can be used for different search aspects e.g. my boss website <title>GaryTheScubaGuy - PPC Manager and Expert</title> <h1><a rel=“nofollow†href="http://ppc-manager.blogspot.com/"> PPC Companies - PPC Managers and Best PPC Companies</a></h1>
It's not a problem having them the same. Many WordPress themes, for example, use the post title as the <title> and <h1> values and they rank just fine. Personally, I tend to make sure the <title> has EXACTLY the keyword phrase(s) that I am targetting since it is the MOST important on-page ranking factor. I ALWAYS maximize the density of my targeted keyword phrase(s) within the <title> element. And if I am targeting 2-3 almost identitcal keyword phrases then I ALWAYS put the most important phrase 1st followed by the 2nd most important followed by the 3rd (if applicable). My <h1> targets the same keyword phrase(s) as the <title> but I'm less concerned with whether the words appear at the front of the <h1> or the end of the <h1> and also less concerned with maximizing the keyword density within the <h1>. My <h1>s tend to be more catchie or marketing driven than the <title>.
No, its not detrimental to have the title tag and the H1 be the exact same text but not using relevant keywords could be...
If I used a competitive keywords for my title i will also use that kw on my H1 . I think that can help.
They can be the same - if someone reads your title in the search results page and clicks through there is no reason why the heading shouldn't be the same. I used to try and make them unique but now I don't bother.